Same problem with ASP and ASPX files. I suspect it's because these features are deprecated.
There are also issues with updating library items and templates to ASP and APSX files. I've wasted an entire morning trying to get templates to update and in the end just had to update each page manually by opening each file and reapplying the templates.
For our studio, Dreamweaver is rapidly going from being a useful, time-saving part of our worklfow to being a complete waste of time if the client site is ASP or ASPX.
I think Adobe have severely underestimated how many CFM, ASP and ASPX website front ends are maintained with Dreamweaver.